Improved process for gilding copper,, brass



UNITED STATES PATENT OFFICE;

GEORGE RICHARDS ELKINGTON, OF BIRMINGHAM, ENGLAND.

Specification forming part of Letters Patent No. 741, dated May 17', 1838.

To all whom it may concern:

Be it known that 1, GEORGE RICHARDS ELKINGTON, a subject of the Queen of Great Britain, and now residingat Birmingham, in the county of Warwick, in the said Kingdom of Great Britain, have invented or discovered a new and Improved Method of Gliding Oopper, Brass, and other Metals orAlloys of Metal; and I, thesaid GEORGERIGHARDS ELKINGTON, do hereby declare the nature of my invention and the manner in which the same is to be performed are fully described and ascertained in and by the following statement thereofthat is to say:

My invention consists in gildiu g copper, brass, and other metals or alloys of metals by means of potash or soda combined with carbonic acid and with a solution of gold, as hereinafter described and in order to myinvention being most fully understood, I will proceed to describe the process as performed by. me, and which has fully answered the purpose, the articles operated on having a very beautiful ap' pearance, and in most instances are considered to be gilded far better than when similar articles have been submitted to the gildin g process where quicksilver is used, the process of gildind by the aidot' quicksilver being well known and in general practice, and as it forms no part of my improved method, but is entirely difi'ereut from my invention, no description of such process will benecessaryin this my specifica'tion.

I will first describe the preparation of the materials and then explain the process of using the same.

Dissolve five ounces, troy weight, offine gold in fifty-two ounces, avoirdupois weight, of nitro-muriaticacid of the following proportions- .videlicet, twenty-one ounces of nitro-acid pure,

of potash of the best quality, let the whole boil moderately for two hours. The mixture will then be ready for use. The liquid being thus prepared, and as in practice it is difiicult to keep the liquid hot in stoneware vessels when many articles are being dipped, I have found it advantageous to transfer the liquid to a cast-iron vessel, which it is necessary to keep very clean. The articles to be gilded having? been first perfectly cleaned from scale or grease, they are to be suspendedon wires conveniently for a workman to dip them in the liquid, which is kept boiling. The time required for gilding any particular article willdepend on circumstances,'partly on the quantity of the gold remaining in theliquid and partly on the size and weight of the article; but alittle practice will readil y produce sufficient judgment to the workman. Supposing the articles desired to be gilded to be brass or copper buttons, or small articles for gilt toys, or ornaments'of dress, such as ear-rings or brace; lets, a considerable number of which may be strung on a hoop or bent piece of copper or brass wire, and dippedinto the vessel containing the boiling liquid above described and moved therein; and the requisite gilding will be generally obtained in from a few seconds to a minute. This is when the liquid is i nthecon-' dition above described, and depending on the quality of the gildin g desired; butif theliquid has been used some time the quantity of gold ed with clean water. They may then be submitted to the usual process of coloring.

It the articles be cast figures of animals or otherwise-a considerable weight compared with the articles above mentioned-the time required to perform the process will be greater.

In case it is desired to produce what is called a dead appearance, it may be performed by several processes. The one I usually employ is to dead the articles-in the process of cleaning, as practiced by brass-founders and other trades, and it is produced by an acid prepared-for that purpose, sold by the makers under the term dca'ding aqua fortis, which is well understood. It may also be produced by a weak solution of nitrate of mercury applied to the articles previous to the gilding process, as is practiced in the process of gilding with mercury previous to spreading the amalgam, but generally a much weaker solution; or the articles having been gilded may be'dipped in a solution of nitrate of mercury and submitted to heat to expel the same, as is practiced in the usual process of gilding.

It is desirable to remark that much of the beauty of the result depends on the wellcleauing of the articles, and it is better to clean them by the ordinary processes and atonce pass them into the liquid to be gilded.

I have always employed the usual means for cleaning the articles from scales and other impurities, which are commonly resorted to in workingof the metals for other purposes, where the surfaces are required to be freed from scales or other impurities,andI would remark that great care should be observed in par chasing the articles above described of the best description.

I have described only the using of bicarbonate of potash, which I believe to be the bestmaterial for the purpose, and I would remark that soda in a state of carbonate may be employed, as also some preparations ofpotash and soda,

, but, so far as my experience goes, not with such advantages as potash in a state of bicarbonate, as above described.

Having now described the nature of my in? vention and the manner of performing the same, I would have it understood that, although in order to give the best information in my power I have stated the exact quantities of the articles employed, I do not confine myself thereto nor do I claim any process for cleaning or (leading; but

WhatI claim as the improved process of gilding is- T-hegilding copper, brass,and other metals or alloys of metals by means of potash or soda, in the state of carbonate or otherwise,

and a solution of gold, as above described. GEORGE RICHARDS ELKINGTON.

Witnesses:

WM. ELKING'ION,

Attorney at Law, Birmingham. J OHN BULLIVAN'I, His- Clerk. 

